The present disclosure relates to a power transmission system that includes a torque converter, a transmission that has a planetary gear and a case that accommodates the torque converter and the transmission.
As a power transmission system of this type, there is conventionally known a power transmission system that has a pump cover making up a bulkhead of a transmission case and a stator shaft connected to a stator of a torque converter via a one-way clutch (for example, refer to JP-A-2001-221300). In this power transmission system, the stator shaft is inserted into a projecting tubular portion that extends towards the transmission from the pump cover to be fixed in place in the projecting tubular portion through serrations and press fitting, and a sun gear of a planetary gear that makes up the transmission is spline connected to an end portion of the stator shaft that lies opposite to an end portion where the stator shaft is connected to the stator. By doing so, the stator shaft and the sun gear, which is a stationary element of the planetary gear, are connected (fixed) to the transmission case via the pump cover so as not to rotate.